WCF服务和添加自定义身份声明

我创建了一些声明并附加它们线程，然后我想访问操作契约GetCurrentUser();用户邮件声明总是返回null。

问题在哪里?

WCF使用本地IIS，绑定类型为wsHttpBinding。

<serviceCredentials>
            <userNameAuthentication userNamePasswordValidationMode="Custom"
              customUserNamePasswordValidatorType="SampleService.UserValidator, SampleService" />
</serviceCredentials>

定制验证器;

public class UserValidator : UserNamePasswordValidator
{
    public override void Validate(string userName, string password)
    {
        if (userName == null || password == null)
        {
            throw new ArgumentNullException();
        }
        if (userName == password)
        {
            var claims = new List<Claim>
                {
                    new Claim(ClaimTypes.Name, "AbbA"),
                    new Claim(ClaimTypes.Email, "foo@bar.com"),
                    new Claim(ClaimTypes.Role,"Customer")
                };
            var id = new ClaimsIdentity(claims, "Sample");
            var principal = new ClaimsPrincipal(id);
            Thread.CurrentPrincipal = principal;
        }
        else
        {
            throw new FaultException("Wrong Password...");
        }
    }
}

And My OperationContract;

    public string GetCurrentUser()
    {
        var principal = Thread.CurrentPrincipal;
        if (principal.Identity.IsAuthenticated)
        {
            var cp = ClaimsPrincipal.Current;
            var email = cp.FindFirst(ClaimTypes.Email).Value; <<<< It's return always null :(
            return string.Format("Your Email is:{0}", email);
        }
        else
        {
            return "NONE";
        }
    }